For Patients

Canasa (mesalamine) is used to treat ulcerative colitis, proctitis, and proctosigmoiditis. It is also used to prevent the symptoms of ulcerative colitis from recurring. It is an anti-inflammatory drug. Common side effects include rectal pain, pain when inserting the suppository, headache, gas, stomach pain, and diarrhea.

The usual dosage of Canasa 1000 mg suppositories is one rectal suppository 1 time daily at bedtime. Other drugs may interact with Canasa rectal. Tell your doctor all prescription and over-the-counter medications and supplements you use. During pregnancy, Canasa should be used only when prescribed. This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

Our Canasa (mesalamine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is Patient Information in Detail?

Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.

SIDE EFFECTS: Rectal pain, pain when inserting the suppository, headache, gas, stomach pain, and diarrhea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Infrequently, this medication may make symptoms of your condition worse rather than better (acute intolerance syndrome or sensitivity reaction). Tell your doctor immediately if you experience any of these unlikely but serious side effects: worsening stomach pain/cramping, worsening bloody diarrhea, fever, severe/prolonged headache.

Tell your doctor immediately if any of these rare but very serious side effects occur: chest pain, trouble breathing, severe stomach/abdominal pain (especially if spreading to the back), change in the amount of urine.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Clinical Trials Experience

Because clinical trials are conducted under widely
varying conditions, adverse reaction rates observed in the clinical trials of a
drug cannot be directly compared to rates in the clinical trials of another
drug and may not reflect the rates observed in practice.

The most frequent adverse reactions observed in the
double-blind, placebo-controlled trials are summarized in the Table 1 below.

In a multicenter, open-label,
randomized, parallel group study comparing the CANASA 1000 mg suppository
administered nightly to that of the CANASA 500 mg suppository twice daily, the
two treatment groups had similar adverse event profiles. The most frequent AEs
were headache (14.4%), flatulence (5.2%), abdominal pain (5.2%), diarrhea
(3.1%), and nausea (3.1%). Three (3) patients had to discontinue medication
because of an adverse reaction; one of these adverse reactions (headache) was
deemed possibly related to study medication.

Postmarketing Experience

In addition to the adverse
reactions reported above in clinical trials involving CANASA, the adverse
reactions listed below have been identified during post-approval use of CANASA
and other mesalamine-containing products. Because these reactions are reported
voluntarily from a population of uncertain size, it is not always possible to
reliably estimate their frequency or establish a causal relationship to drug
exposure.